For most people, the process of applying for Medicare health insurance will be remarkably simple. However, it makes sense to seek a thorough understanding of the enrollment process before it begins, so you can ensure that you know exactly what you need to do at every stage.

In addition to understanding which documents you’ll need when applying for Medicare coverage, it will be useful to understand what the rest of the application process is like. We’ll run through what you need to know about eligibility, as well as enrollment and documentation.

Understanding Medicare Eligibility

To receive Medicare health insurance benefits, you must be eligible. There are slightly different sets of eligibility criteria depending on your overall situation, but understanding eligibility is fairly simple overall.

To be eligible for Medicare, you must be over 65 years old. You can also be under 65 if you have certain disabilities.

For those who are over 65, you must also be eligible for Social Security or Railroad Retirement Board retirement benefits. This doesn’t mean you have to actually receive the benefits, you simply have to be eligible to receive them. You must also be a citizen of the United States or have legal residency for at least five years continuously.

Individuals who are under 65 may be eligible for Medicare if they have certain disabilities. In particular, individuals with End-Stage Renal Disease or certain types of kidney failure can be eligible to receive Medicare benefits. This form of Medicare functions slightly differently from the more common sort available to 65+ year-olds. Medicare.gov contains more information about receiving Medicare when you have a disability.

Understanding the Parts of Medicare

As you begin the enrollment process, it’s very important to be aware of the different types of Medicare that are available. There are four types, known as Part A, Part B, Part C, and Part D, and each functions uniquely. Let’s take a look at each one.

Medicare Part A

Medicare Part A is often referred to as hospital insurance. This is because it covers inpatient hospital care. More accurately, Part A medical insurance simply covers inpatient care, whether this is in a hospital or skilled nursing facility. Part A can also cover hospice care and, in some situations, in-home healthcare.

Part A comes in a premium-free version that most people will be eligible for depending on how long they have paid the Medicare tax for. It is the easiest part of Medicare to enroll in, and most people will be enrolled automatically.

Understanding Medicare Part B

Medicare Part B is the part that most people use most often. Part B covers outpatient healthcare, including things like doctor visits, testing, and so on. Part B will also cover durable medical equipment, or DME.

Along with Part A, Part B is part of “Original Medicare”. This refers to the parts of Medicare that are administered by the federal government. You will usually enroll in Original Medicare all together, meaning that you’ll enroll in Part A and Part B at the same time. If you want to enroll in just one of these, you’ll have to reach out to the Centers of Medicare & Medicaid Services (CMS) or the Social Security Administration (SSA).

Medicare Part C: Medicare Advantage

Medicare Part C is also commonly referred to as Medicare Advantage. Part C health plans don’t cover a specific type of healthcare, can instead be thought of as a way to receive your benefits through private insurance companies. Understanding Part C as a whole can be complex, but it’s worth looking into.

Part C insurance plans are also distinct when it comes to documentation. Because Part C plans are administered by private companies, they may have their own documentation requirements in addition to those required by Medicare as a whole.

If you have Part C, you cannot also enroll in Original Medicare.

Part D: Prescription Drug Coverage

Part D of Medicare, like Part C, is also offered by private insurance companies. Part D drug plans cover prescription drug coverage, which isn’t covered at all by Original Medicare. Because Original Medicare doesn’t cover prescription drugs at all, you can have Part D and Original Medicare at the same time.

Some Medicare Advantage plans also cover prescription drugs. If yours does, then you can’t enroll in a Part D plan at the same time.

How Does Medicare Enrollment Work?

If you’re enrolling in Original Medicare when you turn 65, most of the enrollment process will be automatic. In fact, you may not have to show any documents at all in this situation.

The reason for this is that enrollment goes through Social Security, which already has access to many of your documents. For this reason, Social Security can also automatically set up payment to be deducted from your Social Security check each month, making the entire process seamless and simple.

If you need to enroll manually, you can do so online or contact the Social Security Administration at 1-800-772-1213 (TTY 1-800-325-0778). You can also do this at a local Social Security office. Doing it in person may expedite your enrollment slightly, as the documents can be processed more quickly in some cases.

When to Enroll?

You can’t enroll in Medicare at any time. Instead, there are “enrollment periods” that determine when you can enroll.

Three months before your 65th birthday, you’ll begin your 7-month long Initial Enrollment Period, or IEP. This period consists of three months before your birthday month, the birthday month itself, and three months after. During this time, you'll receive an information packet in the mail along with your Medicare card.

If you already receive Social Security benefits, you’ll be enrolled automatically during this time, and will have to contact Medicare or Social Security to defer your enrollment. If you defer your coverage without good reason, you may face a late enrollment penalty later on.

If you don’t enroll during the IEP, you can also enroll during the Annual Enrollment Period. In addition to this, some people will be able to enroll during a General Enrollment Period, lasting from January 1st to March 31st of each year, or during a Special Enrollment Period. The Special Enrollment Period is a period that occurs when you experience certain life events like moving, getting married, or changing your employment status.

Which Documents May I Need to Use?

If Medicare and Social Security don’t have certain information about you, there are certain documents they may ask to see. As we mentioned above, plenty of people enroll successfully without needing to show these documents.

The only documents you’re likely to be asked for are a birth certificate, your driver's license or government ID, and some form or proof of citizenship. You may also need to fill out certain paperwork depending on what you’re trying to do, but in most cases, not much documentation is needed.

If you are enrolling for Medicare due to disability, you may have to provide additional documents from your healthcare provider.

Final Thoughts on Medicare and Documentation

As you can see, documentation is probably the easiest part of enrolling in Medicare. When you enroll, most of the process can be automatic, and the list of documents that may be required is fairly short. The important things to remember are just to keep on top of your Initial Enrollment Period and to make sure that you know at which stage you are at.